1. Field of the Invention
This invention relates to a maintenance device in an ink jet printing apparatus and, in particular, to a capping mechanism and a wiper arrangement in the maintenance device.
2. Description of the Related Art
The maintenance device in an ink jet printing apparatus is generally disposed at an end of the printing apparatus. Because printing cannot be performed in the area above the maintenance device, it is advantageous to minimize the size of the maintenance device to reduce the overall size of the printing apparatus and to increase a space where printing can be performed.
A maintenance device in an ink jet printing apparatus generally performs maintenance operations to preserve the life of the ink jet head. The maintenance device includes a wiper for wiping residual ink from the nozzles of the ink jet head after completion of printing and a capping mechanism to cap the ink jet head for storage. The wiping and capping operations prevent the nozzles from becoming blocked and extend the life of the ink jet head.
One such maintenance device is described in U.S. Pat. No. 5,202,762 to Terasawa et al. (Terasawa hereinafter). Terasawa describes a method and apparatus for cleaning an ink jet recording head using a flexible blade that is moved forwardly and backwardly in response to the capping operation of the front surface of the recording head and the movement of a carriage. The front surface of the recording head is wiped by the blade in response to the movement of the carriage. A problem arises in Terasawa, however, in that the blade and capping mechanism are moved forwardly and backwardly by at least one actuator, thereby increasing the manufacturing costs of the apparatus. In addition, because of the proximity of the blade and the capping mechanism, a situation may arise where the blade is deflected by the printing carriage into the path of the capping mechanism so as to be pinched between the capping mechanism and the recording head in the standby position.
To lower the cost of the apparatus, there has been disclosed a device that operates without the use of a separate actuator for the wiping and/or capping functions. U.S. Pat. No. 4,533,927 to Iwagami et al. (Iwagami hereinafter) describes an ink jet system printer including a capping mechanism for covering a printer head when a carriage is located at a standby position. The capping mechanism includes a cap member supported by a slidable plate that is Shifted toward the printer head as the printer head moves to the standby position through the use of links. The slidable plate is shifted by the traveling force of the carriage so that a separate drive source is not required. Iwagami, howewer, relies on the use of a large number of parts and relies on springs to perform the capping action. In addition, Iwagami does not suggest a way to reduce a size of a maintenance device including a capping mechanism and a wiper.